Euphorbia is a very large and diverse genus of flowering plants, commonly called spurge, in the spurge family. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae, not just to members of the genus.
Euphorbia plants provide them light, moderate moisture, and watch for annoying pests, like whitefly. Provide water under the plant's leaves to prevent powdery mildew. You will not need to fertilize Spurge often.